For all their sibling squabbles Fortnum and Mason are best of friends.  They are never entirely comfortable when they are separated even if they can see each other on the other side of the gate.  What I find fascinating is that every time they are apart – even if it’s just a short while they always check each other out fully (sniffing all the important signal points) before being reassured that they are in fact reunited with the right dog. That would be the dog that they share almost every waking and every sleeping hour together.  But you can never be too sure!